ip_output.c revision 1.167.2.2
1 /* $NetBSD: ip_output.c,v 1.167.2.2 2007/03/28 20:46:13 jdc Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /*- 33 * Copyright (c) 1998 The NetBSD Foundation, Inc. 34 * All rights reserved. 35 * 36 * This code is derived from software contributed to The NetBSD Foundation 37 * by Public Access Networks Corporation ("Panix"). It was developed under 38 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 3. All advertising materials mentioning features or use of this software 49 * must display the following acknowledgement: 50 * This product includes software developed by the NetBSD 51 * Foundation, Inc. and its contributors. 52 * 4. Neither the name of The NetBSD Foundation nor the names of its 53 * contributors may be used to endorse or promote products derived 54 * from this software without specific prior written permission. 55 * 56 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 57 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 58 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 59 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 60 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 61 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 62 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 63 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 64 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 65 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 66 * POSSIBILITY OF SUCH DAMAGE. 67 */ 68 69 /* 70 * Copyright (c) 1982, 1986, 1988, 1990, 1993 71 * The Regents of the University of California. All rights reserved. 72 * 73 * Redistribution and use in source and binary forms, with or without 74 * modification, are permitted provided that the following conditions 75 * are met: 76 * 1. Redistributions of source code must retain the above copyright 77 * notice, this list of conditions and the following disclaimer. 78 * 2. Redistributions in binary form must reproduce the above copyright 79 * notice, this list of conditions and the following disclaimer in the 80 * documentation and/or other materials provided with the distribution. 81 * 3. Neither the name of the University nor the names of its contributors 82 * may be used to endorse or promote products derived from this software 83 * without specific prior written permission. 84 * 85 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 86 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 87 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 88 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 89 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 90 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 91 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 92 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 93 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 94 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 95 * SUCH DAMAGE. 96 * 97 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 98 */ 99 100 #include <sys/cdefs.h> 101 __KERNEL_RCSID(0, "$NetBSD: ip_output.c,v 1.167.2.2 2007/03/28 20:46:13 jdc Exp $"); 102 103 #include "opt_pfil_hooks.h" 104 #include "opt_inet.h" 105 #include "opt_ipsec.h" 106 #include "opt_mrouting.h" 107 108 #include <sys/param.h> 109 #include <sys/malloc.h> 110 #include <sys/mbuf.h> 111 #include <sys/errno.h> 112 #include <sys/protosw.h> 113 #include <sys/socket.h> 114 #include <sys/socketvar.h> 115 #include <sys/kauth.h> 116 #ifdef FAST_IPSEC 117 #include <sys/domain.h> 118 #endif 119 #include <sys/systm.h> 120 #include <sys/proc.h> 121 122 #include <net/if.h> 123 #include <net/route.h> 124 #include <net/pfil.h> 125 126 #include <netinet/in.h> 127 #include <netinet/in_systm.h> 128 #include <netinet/ip.h> 129 #include <netinet/in_pcb.h> 130 #include <netinet/in_var.h> 131 #include <netinet/ip_var.h> 132 #include <netinet/in_offload.h> 133 134 #ifdef MROUTING 135 #include <netinet/ip_mroute.h> 136 #endif 137 138 #include <machine/stdarg.h> 139 140 #ifdef IPSEC 141 #include <netinet6/ipsec.h> 142 #include <netkey/key.h> 143 #include <netkey/key_debug.h> 144 #endif /*IPSEC*/ 145 146 #ifdef FAST_IPSEC 147 #include <netipsec/ipsec.h> 148 #include <netipsec/key.h> 149 #include <netipsec/xform.h> 150 #endif /* FAST_IPSEC*/ 151 152 #ifdef IPSEC_NAT_T 153 #include <netinet/udp.h> 154 #endif 155 156 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 157 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 158 static void ip_mloopback(struct ifnet *, struct mbuf *, struct sockaddr_in *); 159 static int ip_getoptval(struct mbuf *, u_int8_t *, u_int); 160 161 #ifdef PFIL_HOOKS 162 extern struct pfil_head inet_pfil_hook; /* XXX */ 163 #endif 164 165 int ip_do_loopback_cksum = 0; 166 167 #define IN_NEED_CHECKSUM(ifp, csum_flags) \ 168 (__predict_true(((ifp)->if_flags & IFF_LOOPBACK) == 0 || \ 169 (((csum_flags) & M_CSUM_UDPv4) != 0 && udp_do_loopback_cksum) || \ 170 (((csum_flags) & M_CSUM_TCPv4) != 0 && tcp_do_loopback_cksum) || \ 171 (((csum_flags) & M_CSUM_IPv4) != 0 && ip_do_loopback_cksum))) 172 173 /* 174 * IP output. The packet in mbuf chain m contains a skeletal IP 175 * header (with len, off, ttl, proto, tos, src, dst). 176 * The mbuf chain containing the packet will be freed. 177 * The mbuf opt, if present, will not be freed. 178 */ 179 int 180 ip_output(struct mbuf *m0, ...) 181 { 182 struct ip *ip; 183 struct ifnet *ifp; 184 struct mbuf *m = m0; 185 int hlen = sizeof (struct ip); 186 int len, error = 0; 187 struct route iproute; 188 struct sockaddr_in *dst; 189 struct in_ifaddr *ia; 190 struct ifaddr *xifa; 191 struct mbuf *opt; 192 struct route *ro; 193 int flags, sw_csum; 194 int *mtu_p; 195 u_long mtu; 196 struct ip_moptions *imo; 197 struct socket *so; 198 va_list ap; 199 #ifdef IPSEC_NAT_T 200 int natt_frag = 0; 201 #endif 202 #ifdef IPSEC 203 struct secpolicy *sp = NULL; 204 #endif /*IPSEC*/ 205 #ifdef FAST_IPSEC 206 struct inpcb *inp; 207 struct m_tag *mtag; 208 struct secpolicy *sp = NULL; 209 struct tdb_ident *tdbi; 210 int s; 211 #endif 212 u_int16_t ip_len; 213 214 len = 0; 215 va_start(ap, m0); 216 opt = va_arg(ap, struct mbuf *); 217 ro = va_arg(ap, struct route *); 218 flags = va_arg(ap, int); 219 imo = va_arg(ap, struct ip_moptions *); 220 so = va_arg(ap, struct socket *); 221 if (flags & IP_RETURNMTU) 222 mtu_p = va_arg(ap, int *); 223 else 224 mtu_p = NULL; 225 va_end(ap); 226 227 MCLAIM(m, &ip_tx_mowner); 228 #ifdef FAST_IPSEC 229 if (so != NULL && so->so_proto->pr_domain->dom_family == AF_INET) 230 inp = (struct inpcb *)so->so_pcb; 231 else 232 inp = NULL; 233 #endif /* FAST_IPSEC */ 234 235 #ifdef DIAGNOSTIC 236 if ((m->m_flags & M_PKTHDR) == 0) 237 panic("ip_output: no HDR"); 238 239 if ((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) != 0) { 240 panic("ip_output: IPv6 checksum offload flags: %d", 241 m->m_pkthdr.csum_flags); 242 } 243 244 if ((m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) == 245 (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 246 panic("ip_output: conflicting checksum offload flags: %d", 247 m->m_pkthdr.csum_flags); 248 } 249 #endif 250 if (opt) { 251 m = ip_insertoptions(m, opt, &len); 252 if (len >= sizeof(struct ip)) 253 hlen = len; 254 } 255 ip = mtod(m, struct ip *); 256 /* 257 * Fill in IP header. 258 */ 259 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 260 ip->ip_v = IPVERSION; 261 ip->ip_off = htons(0); 262 if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 263 ip->ip_id = ip_newid(); 264 } else { 265 266 /* 267 * TSO capable interfaces (typically?) increment 268 * ip_id for each segment. 269 * "allocate" enough ids here to increase the chance 270 * for them to be unique. 271 * 272 * note that the following calculation is not 273 * needed to be precise. wasting some ip_id is fine. 274 */ 275 276 unsigned int segsz = m->m_pkthdr.segsz; 277 unsigned int datasz = ntohs(ip->ip_len) - hlen; 278 unsigned int num = howmany(datasz, segsz); 279 280 ip->ip_id = ip_newid_range(num); 281 } 282 ip->ip_hl = hlen >> 2; 283 ipstat.ips_localout++; 284 } else { 285 hlen = ip->ip_hl << 2; 286 } 287 /* 288 * Route packet. 289 */ 290 bzero(&iproute, sizeof(iproute)); 291 if (ro == NULL) 292 ro = &iproute; 293 dst = satosin(&ro->ro_dst); 294 /* 295 * If there is a cached route, 296 * check that it is to the same destination 297 * and is still up. If not, free it and try again. 298 * The address family should also be checked in case of sharing the 299 * cache with IPv6. 300 */ 301 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 302 dst->sin_family != AF_INET || 303 !in_hosteq(dst->sin_addr, ip->ip_dst))) { 304 RTFREE(ro->ro_rt); 305 ro->ro_rt = (struct rtentry *)0; 306 } 307 if (ro->ro_rt == 0) { 308 bzero(dst, sizeof(*dst)); 309 dst->sin_family = AF_INET; 310 dst->sin_len = sizeof(*dst); 311 dst->sin_addr = ip->ip_dst; 312 } 313 /* 314 * If routing to interface only, 315 * short circuit routing lookup. 316 */ 317 if (flags & IP_ROUTETOIF) { 318 if ((ia = ifatoia(ifa_ifwithladdr(sintosa(dst)))) == 0) { 319 ipstat.ips_noroute++; 320 error = ENETUNREACH; 321 goto bad; 322 } 323 ifp = ia->ia_ifp; 324 mtu = ifp->if_mtu; 325 ip->ip_ttl = 1; 326 } else if ((IN_MULTICAST(ip->ip_dst.s_addr) || 327 ip->ip_dst.s_addr == INADDR_BROADCAST) && 328 imo != NULL && imo->imo_multicast_ifp != NULL) { 329 ifp = imo->imo_multicast_ifp; 330 mtu = ifp->if_mtu; 331 IFP_TO_IA(ifp, ia); 332 } else { 333 if (ro->ro_rt == 0) 334 rtalloc(ro); 335 if (ro->ro_rt == 0) { 336 ipstat.ips_noroute++; 337 error = EHOSTUNREACH; 338 goto bad; 339 } 340 ia = ifatoia(ro->ro_rt->rt_ifa); 341 ifp = ro->ro_rt->rt_ifp; 342 if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) 343 mtu = ifp->if_mtu; 344 ro->ro_rt->rt_use++; 345 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 346 dst = satosin(ro->ro_rt->rt_gateway); 347 } 348 if (IN_MULTICAST(ip->ip_dst.s_addr) || 349 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 350 struct in_multi *inm; 351 352 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 353 M_BCAST : M_MCAST; 354 /* 355 * IP destination address is multicast. Make sure "dst" 356 * still points to the address in "ro". (It may have been 357 * changed to point to a gateway address, above.) 358 */ 359 dst = satosin(&ro->ro_dst); 360 /* 361 * See if the caller provided any multicast options 362 */ 363 if (imo != NULL) 364 ip->ip_ttl = imo->imo_multicast_ttl; 365 else 366 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 367 368 /* 369 * if we don't know the outgoing ifp yet, we can't generate 370 * output 371 */ 372 if (!ifp) { 373 ipstat.ips_noroute++; 374 error = ENETUNREACH; 375 goto bad; 376 } 377 378 /* 379 * If the packet is multicast or broadcast, confirm that 380 * the outgoing interface can transmit it. 381 */ 382 if (((m->m_flags & M_MCAST) && 383 (ifp->if_flags & IFF_MULTICAST) == 0) || 384 ((m->m_flags & M_BCAST) && 385 (ifp->if_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)) { 386 ipstat.ips_noroute++; 387 error = ENETUNREACH; 388 goto bad; 389 } 390 /* 391 * If source address not specified yet, use an address 392 * of outgoing interface. 393 */ 394 if (in_nullhost(ip->ip_src)) { 395 struct in_ifaddr *xia; 396 397 IFP_TO_IA(ifp, xia); 398 if (!xia) { 399 error = EADDRNOTAVAIL; 400 goto bad; 401 } 402 xifa = &xia->ia_ifa; 403 if (xifa->ifa_getifa != NULL) { 404 xia = ifatoia((*xifa->ifa_getifa)(xifa, 405 &ro->ro_dst)); 406 } 407 ip->ip_src = xia->ia_addr.sin_addr; 408 } 409 410 IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); 411 if (inm != NULL && 412 (imo == NULL || imo->imo_multicast_loop)) { 413 /* 414 * If we belong to the destination multicast group 415 * on the outgoing interface, and the caller did not 416 * forbid loopback, loop back a copy. 417 */ 418 ip_mloopback(ifp, m, dst); 419 } 420 #ifdef MROUTING 421 else { 422 /* 423 * If we are acting as a multicast router, perform 424 * multicast forwarding as if the packet had just 425 * arrived on the interface to which we are about 426 * to send. The multicast forwarding function 427 * recursively calls this function, using the 428 * IP_FORWARDING flag to prevent infinite recursion. 429 * 430 * Multicasts that are looped back by ip_mloopback(), 431 * above, will be forwarded by the ip_input() routine, 432 * if necessary. 433 */ 434 extern struct socket *ip_mrouter; 435 436 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 437 if (ip_mforward(m, ifp) != 0) { 438 m_freem(m); 439 goto done; 440 } 441 } 442 } 443 #endif 444 /* 445 * Multicasts with a time-to-live of zero may be looped- 446 * back, above, but must not be transmitted on a network. 447 * Also, multicasts addressed to the loopback interface 448 * are not sent -- the above call to ip_mloopback() will 449 * loop back a copy if this host actually belongs to the 450 * destination group on the loopback interface. 451 */ 452 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 453 m_freem(m); 454 goto done; 455 } 456 457 goto sendit; 458 } 459 /* 460 * If source address not specified yet, use address 461 * of outgoing interface. 462 */ 463 if (in_nullhost(ip->ip_src)) { 464 xifa = &ia->ia_ifa; 465 if (xifa->ifa_getifa != NULL) 466 ia = ifatoia((*xifa->ifa_getifa)(xifa, &ro->ro_dst)); 467 ip->ip_src = ia->ia_addr.sin_addr; 468 } 469 470 /* 471 * packets with Class-D address as source are not valid per 472 * RFC 1112 473 */ 474 if (IN_MULTICAST(ip->ip_src.s_addr)) { 475 ipstat.ips_odropped++; 476 error = EADDRNOTAVAIL; 477 goto bad; 478 } 479 480 /* 481 * Look for broadcast address and 482 * and verify user is allowed to send 483 * such a packet. 484 */ 485 if (in_broadcast(dst->sin_addr, ifp)) { 486 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 487 error = EADDRNOTAVAIL; 488 goto bad; 489 } 490 if ((flags & IP_ALLOWBROADCAST) == 0) { 491 error = EACCES; 492 goto bad; 493 } 494 /* don't allow broadcast messages to be fragmented */ 495 if (ntohs(ip->ip_len) > ifp->if_mtu) { 496 error = EMSGSIZE; 497 goto bad; 498 } 499 m->m_flags |= M_BCAST; 500 } else 501 m->m_flags &= ~M_BCAST; 502 503 sendit: 504 /* 505 * If we're doing Path MTU Discovery, we need to set DF unless 506 * the route's MTU is locked. 507 */ 508 if ((flags & IP_MTUDISC) != 0 && ro->ro_rt != NULL && 509 (ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0) 510 ip->ip_off |= htons(IP_DF); 511 512 /* Remember the current ip_len */ 513 ip_len = ntohs(ip->ip_len); 514 515 #ifdef IPSEC 516 /* get SP for this packet */ 517 if (so == NULL) 518 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 519 flags, &error); 520 else { 521 if (IPSEC_PCB_SKIP_IPSEC(sotoinpcb_hdr(so)->inph_sp, 522 IPSEC_DIR_OUTBOUND)) 523 goto skip_ipsec; 524 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); 525 } 526 527 if (sp == NULL) { 528 ipsecstat.out_inval++; 529 goto bad; 530 } 531 532 error = 0; 533 534 /* check policy */ 535 switch (sp->policy) { 536 case IPSEC_POLICY_DISCARD: 537 /* 538 * This packet is just discarded. 539 */ 540 ipsecstat.out_polvio++; 541 goto bad; 542 543 case IPSEC_POLICY_BYPASS: 544 case IPSEC_POLICY_NONE: 545 /* no need to do IPsec. */ 546 goto skip_ipsec; 547 548 case IPSEC_POLICY_IPSEC: 549 if (sp->req == NULL) { 550 /* XXX should be panic ? */ 551 printf("ip_output: No IPsec request specified.\n"); 552 error = EINVAL; 553 goto bad; 554 } 555 break; 556 557 case IPSEC_POLICY_ENTRUST: 558 default: 559 printf("ip_output: Invalid policy found. %d\n", sp->policy); 560 } 561 562 #ifdef IPSEC_NAT_T 563 /* 564 * NAT-T ESP fragmentation: don't do IPSec processing now, 565 * we'll do it on each fragmented packet. 566 */ 567 if (sp->req->sav && 568 ((sp->req->sav->natt_type & UDP_ENCAP_ESPINUDP) || 569 (sp->req->sav->natt_type & UDP_ENCAP_ESPINUDP_NON_IKE))) { 570 if (ntohs(ip->ip_len) > sp->req->sav->esp_frag) { 571 natt_frag = 1; 572 mtu = sp->req->sav->esp_frag; 573 goto skip_ipsec; 574 } 575 } 576 #endif /* IPSEC_NAT_T */ 577 578 /* 579 * ipsec4_output() expects ip_len and ip_off in network 580 * order. They have been set to network order above. 581 */ 582 583 { 584 struct ipsec_output_state state; 585 bzero(&state, sizeof(state)); 586 state.m = m; 587 if (flags & IP_ROUTETOIF) { 588 state.ro = &iproute; 589 bzero(&iproute, sizeof(iproute)); 590 } else 591 state.ro = ro; 592 state.dst = (struct sockaddr *)dst; 593 594 /* 595 * We can't defer the checksum of payload data if 596 * we're about to encrypt/authenticate it. 597 * 598 * XXX When we support crypto offloading functions of 599 * XXX network interfaces, we need to reconsider this, 600 * XXX since it's likely that they'll support checksumming, 601 * XXX as well. 602 */ 603 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 604 in_delayed_cksum(m); 605 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 606 } 607 608 error = ipsec4_output(&state, sp, flags); 609 610 m = state.m; 611 if (flags & IP_ROUTETOIF) { 612 /* 613 * if we have tunnel mode SA, we may need to ignore 614 * IP_ROUTETOIF. 615 */ 616 if (state.ro != &iproute || state.ro->ro_rt != NULL) { 617 flags &= ~IP_ROUTETOIF; 618 ro = state.ro; 619 } 620 } else 621 ro = state.ro; 622 dst = (struct sockaddr_in *)state.dst; 623 if (error) { 624 /* mbuf is already reclaimed in ipsec4_output. */ 625 m0 = NULL; 626 switch (error) { 627 case EHOSTUNREACH: 628 case ENETUNREACH: 629 case EMSGSIZE: 630 case ENOBUFS: 631 case ENOMEM: 632 break; 633 default: 634 printf("ip4_output (ipsec): error code %d\n", error); 635 /*fall through*/ 636 case ENOENT: 637 /* don't show these error codes to the user */ 638 error = 0; 639 break; 640 } 641 goto bad; 642 } 643 644 /* be sure to update variables that are affected by ipsec4_output() */ 645 ip = mtod(m, struct ip *); 646 hlen = ip->ip_hl << 2; 647 ip_len = ntohs(ip->ip_len); 648 649 if (ro->ro_rt == NULL) { 650 if ((flags & IP_ROUTETOIF) == 0) { 651 printf("ip_output: " 652 "can't update route after IPsec processing\n"); 653 error = EHOSTUNREACH; /*XXX*/ 654 goto bad; 655 } 656 } else { 657 /* nobody uses ia beyond here */ 658 if (state.encap) { 659 ifp = ro->ro_rt->rt_ifp; 660 if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) 661 mtu = ifp->if_mtu; 662 } 663 } 664 } 665 skip_ipsec: 666 #endif /*IPSEC*/ 667 #ifdef FAST_IPSEC 668 /* 669 * Check the security policy (SP) for the packet and, if 670 * required, do IPsec-related processing. There are two 671 * cases here; the first time a packet is sent through 672 * it will be untagged and handled by ipsec4_checkpolicy. 673 * If the packet is resubmitted to ip_output (e.g. after 674 * AH, ESP, etc. processing), there will be a tag to bypass 675 * the lookup and related policy checking. 676 */ 677 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); 678 s = splsoftnet(); 679 if (mtag != NULL) { 680 tdbi = (struct tdb_ident *)(mtag + 1); 681 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); 682 if (sp == NULL) 683 error = -EINVAL; /* force silent drop */ 684 m_tag_delete(m, mtag); 685 } else { 686 if (inp != NULL && 687 IPSEC_PCB_SKIP_IPSEC(inp->inp_sp, IPSEC_DIR_OUTBOUND)) 688 goto spd_done; 689 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, 690 &error, inp); 691 } 692 /* 693 * There are four return cases: 694 * sp != NULL apply IPsec policy 695 * sp == NULL, error == 0 no IPsec handling needed 696 * sp == NULL, error == -EINVAL discard packet w/o error 697 * sp == NULL, error != 0 discard packet, report error 698 */ 699 if (sp != NULL) { 700 #ifdef IPSEC_NAT_T 701 /* 702 * NAT-T ESP fragmentation: don't do IPSec processing now, 703 * we'll do it on each fragmented packet. 704 */ 705 if (sp->req->sav && 706 ((sp->req->sav->natt_type & UDP_ENCAP_ESPINUDP) || 707 (sp->req->sav->natt_type & UDP_ENCAP_ESPINUDP_NON_IKE))) { 708 if (ntohs(ip->ip_len) > sp->req->sav->esp_frag) { 709 natt_frag = 1; 710 mtu = sp->req->sav->esp_frag; 711 goto spd_done; 712 } 713 } 714 #endif /* IPSEC_NAT_T */ 715 /* Loop detection, check if ipsec processing already done */ 716 IPSEC_ASSERT(sp->req != NULL, ("ip_output: no ipsec request")); 717 for (mtag = m_tag_first(m); mtag != NULL; 718 mtag = m_tag_next(m, mtag)) { 719 #ifdef MTAG_ABI_COMPAT 720 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) 721 continue; 722 #endif 723 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && 724 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) 725 continue; 726 /* 727 * Check if policy has an SA associated with it. 728 * This can happen when an SP has yet to acquire 729 * an SA; e.g. on first reference. If it occurs, 730 * then we let ipsec4_process_packet do its thing. 731 */ 732 if (sp->req->sav == NULL) 733 break; 734 tdbi = (struct tdb_ident *)(mtag + 1); 735 if (tdbi->spi == sp->req->sav->spi && 736 tdbi->proto == sp->req->sav->sah->saidx.proto && 737 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, 738 sizeof (union sockaddr_union)) == 0) { 739 /* 740 * No IPsec processing is needed, free 741 * reference to SP. 742 * 743 * NB: null pointer to avoid free at 744 * done: below. 745 */ 746 KEY_FREESP(&sp), sp = NULL; 747 splx(s); 748 goto spd_done; 749 } 750 } 751 752 /* 753 * Do delayed checksums now because we send before 754 * this is done in the normal processing path. 755 */ 756 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 757 in_delayed_cksum(m); 758 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 759 } 760 761 #ifdef __FreeBSD__ 762 ip->ip_len = htons(ip->ip_len); 763 ip->ip_off = htons(ip->ip_off); 764 #endif 765 766 /* NB: callee frees mbuf */ 767 error = ipsec4_process_packet(m, sp->req, flags, 0); 768 /* 769 * Preserve KAME behaviour: ENOENT can be returned 770 * when an SA acquire is in progress. Don't propagate 771 * this to user-level; it confuses applications. 772 * 773 * XXX this will go away when the SADB is redone. 774 */ 775 if (error == ENOENT) 776 error = 0; 777 splx(s); 778 goto done; 779 } else { 780 splx(s); 781 782 if (error != 0) { 783 /* 784 * Hack: -EINVAL is used to signal that a packet 785 * should be silently discarded. This is typically 786 * because we asked key management for an SA and 787 * it was delayed (e.g. kicked up to IKE). 788 */ 789 if (error == -EINVAL) 790 error = 0; 791 goto bad; 792 } else { 793 /* No IPsec processing for this packet. */ 794 } 795 #ifdef notyet 796 /* 797 * If deferred crypto processing is needed, check that 798 * the interface supports it. 799 */ 800 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); 801 if (mtag != NULL && (ifp->if_capenable & IFCAP_IPSEC) == 0) { 802 /* notify IPsec to do its own crypto */ 803 ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1)); 804 error = EHOSTUNREACH; 805 goto bad; 806 } 807 #endif 808 } 809 spd_done: 810 #endif /* FAST_IPSEC */ 811 812 #ifdef PFIL_HOOKS 813 /* 814 * Run through list of hooks for output packets. 815 */ 816 if ((error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT)) != 0) 817 goto done; 818 if (m == NULL) 819 goto done; 820 821 ip = mtod(m, struct ip *); 822 hlen = ip->ip_hl << 2; 823 ip_len = ntohs(ip->ip_len); 824 #endif /* PFIL_HOOKS */ 825 826 m->m_pkthdr.csum_data |= hlen << 16; 827 828 #if IFA_STATS 829 /* 830 * search for the source address structure to 831 * maintain output statistics. 832 */ 833 INADDR_TO_IA(ip->ip_src, ia); 834 #endif 835 836 /* Maybe skip checksums on loopback interfaces. */ 837 if (IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) { 838 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 839 } 840 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 841 /* 842 * If small enough for mtu of path, or if using TCP segmentation 843 * offload, can just send directly. 844 */ 845 if (ip_len <= mtu || 846 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0) { 847 #if IFA_STATS 848 if (ia) 849 ia->ia_ifa.ifa_data.ifad_outbytes += ip_len; 850 #endif 851 /* 852 * Always initialize the sum to 0! Some HW assisted 853 * checksumming requires this. 854 */ 855 ip->ip_sum = 0; 856 857 if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 858 /* 859 * Perform any checksums that the hardware can't do 860 * for us. 861 * 862 * XXX Does any hardware require the {th,uh}_sum 863 * XXX fields to be 0? 864 */ 865 if (sw_csum & M_CSUM_IPv4) { 866 KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)); 867 ip->ip_sum = in_cksum(m, hlen); 868 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 869 } 870 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 871 if (IN_NEED_CHECKSUM(ifp, 872 sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 873 in_delayed_cksum(m); 874 } 875 m->m_pkthdr.csum_flags &= 876 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 877 } 878 } 879 880 #ifdef IPSEC 881 /* clean ipsec history once it goes out of the node */ 882 ipsec_delaux(m); 883 #endif 884 885 if (__predict_true( 886 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0 || 887 (ifp->if_capenable & IFCAP_TSOv4) != 0)) { 888 error = 889 (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt); 890 } else { 891 error = 892 ip_tso_output(ifp, m, sintosa(dst), ro->ro_rt); 893 } 894 goto done; 895 } 896 897 /* 898 * We can't use HW checksumming if we're about to 899 * to fragment the packet. 900 * 901 * XXX Some hardware can do this. 902 */ 903 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 904 if (IN_NEED_CHECKSUM(ifp, 905 m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 906 in_delayed_cksum(m); 907 } 908 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 909 } 910 911 /* 912 * Too large for interface; fragment if possible. 913 * Must be able to put at least 8 bytes per fragment. 914 */ 915 if (ntohs(ip->ip_off) & IP_DF) { 916 if (flags & IP_RETURNMTU) 917 *mtu_p = mtu; 918 error = EMSGSIZE; 919 ipstat.ips_cantfrag++; 920 goto bad; 921 } 922 923 error = ip_fragment(m, ifp, mtu); 924 if (error) { 925 m = NULL; 926 goto bad; 927 } 928 929 for (; m; m = m0) { 930 m0 = m->m_nextpkt; 931 m->m_nextpkt = 0; 932 if (error == 0) { 933 #if IFA_STATS 934 if (ia) 935 ia->ia_ifa.ifa_data.ifad_outbytes += 936 ntohs(ip->ip_len); 937 #endif 938 #ifdef IPSEC 939 /* clean ipsec history once it goes out of the node */ 940 ipsec_delaux(m); 941 #endif /* IPSEC */ 942 943 #ifdef IPSEC_NAT_T 944 /* 945 * If we get there, the packet has not been handeld by 946 * IPSec whereas it should have. Now that it has been 947 * fragmented, re-inject it in ip_output so that IPsec 948 * processing can occur. 949 */ 950 if (natt_frag) { 951 error = ip_output(m, opt, 952 ro, flags, imo, so, mtu_p); 953 } else 954 #endif /* IPSEC_NAT_T */ 955 { 956 KASSERT((m->m_pkthdr.csum_flags & 957 (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0); 958 error = (*ifp->if_output)(ifp, m, sintosa(dst), 959 ro->ro_rt); 960 } 961 } else 962 m_freem(m); 963 } 964 965 if (error == 0) 966 ipstat.ips_fragmented++; 967 done: 968 if (iproute.ro_rt != NULL) 969 RTFREE(iproute.ro_rt); 970 971 #ifdef IPSEC 972 if (sp != NULL) { 973 KEYDEBUG(KEYDEBUG_IPSEC_STAMP, 974 printf("DP ip_output call free SP:%p\n", sp)); 975 key_freesp(sp); 976 } 977 #endif /* IPSEC */ 978 #ifdef FAST_IPSEC 979 if (sp != NULL) 980 KEY_FREESP(&sp); 981 #endif /* FAST_IPSEC */ 982 983 return (error); 984 bad: 985 m_freem(m); 986 goto done; 987 } 988 989 int 990 ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) 991 { 992 struct ip *ip, *mhip; 993 struct mbuf *m0; 994 int len, hlen, off; 995 int mhlen, firstlen; 996 struct mbuf **mnext; 997 int sw_csum = m->m_pkthdr.csum_flags; 998 int fragments = 0; 999 int s; 1000 int error = 0; 1001 1002 ip = mtod(m, struct ip *); 1003 hlen = ip->ip_hl << 2; 1004 if (ifp != NULL) 1005 sw_csum &= ~ifp->if_csum_flags_tx; 1006 1007 len = (mtu - hlen) &~ 7; 1008 if (len < 8) { 1009 m_freem(m); 1010 return (EMSGSIZE); 1011 } 1012 1013 firstlen = len; 1014 mnext = &m->m_nextpkt; 1015 1016 /* 1017 * Loop through length of segment after first fragment, 1018 * make new header and copy data of each part and link onto chain. 1019 */ 1020 m0 = m; 1021 mhlen = sizeof (struct ip); 1022 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { 1023 MGETHDR(m, M_DONTWAIT, MT_HEADER); 1024 if (m == 0) { 1025 error = ENOBUFS; 1026 ipstat.ips_odropped++; 1027 goto sendorfree; 1028 } 1029 MCLAIM(m, m0->m_owner); 1030 *mnext = m; 1031 mnext = &m->m_nextpkt; 1032 m->m_data += max_linkhdr; 1033 mhip = mtod(m, struct ip *); 1034 *mhip = *ip; 1035 /* we must inherit MCAST and BCAST flags */ 1036 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 1037 if (hlen > sizeof (struct ip)) { 1038 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 1039 mhip->ip_hl = mhlen >> 2; 1040 } 1041 m->m_len = mhlen; 1042 mhip->ip_off = ((off - hlen) >> 3) + 1043 (ntohs(ip->ip_off) & ~IP_MF); 1044 if (ip->ip_off & htons(IP_MF)) 1045 mhip->ip_off |= IP_MF; 1046 if (off + len >= ntohs(ip->ip_len)) 1047 len = ntohs(ip->ip_len) - off; 1048 else 1049 mhip->ip_off |= IP_MF; 1050 HTONS(mhip->ip_off); 1051 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 1052 m->m_next = m_copy(m0, off, len); 1053 if (m->m_next == 0) { 1054 error = ENOBUFS; /* ??? */ 1055 ipstat.ips_odropped++; 1056 goto sendorfree; 1057 } 1058 m->m_pkthdr.len = mhlen + len; 1059 m->m_pkthdr.rcvif = (struct ifnet *)0; 1060 mhip->ip_sum = 0; 1061 if (sw_csum & M_CSUM_IPv4) { 1062 mhip->ip_sum = in_cksum(m, mhlen); 1063 KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0); 1064 } else { 1065 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 1066 m->m_pkthdr.csum_data |= mhlen << 16; 1067 } 1068 ipstat.ips_ofragments++; 1069 fragments++; 1070 } 1071 /* 1072 * Update first fragment by trimming what's been copied out 1073 * and updating header, then send each fragment (in order). 1074 */ 1075 m = m0; 1076 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 1077 m->m_pkthdr.len = hlen + firstlen; 1078 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 1079 ip->ip_off |= htons(IP_MF); 1080 ip->ip_sum = 0; 1081 if (sw_csum & M_CSUM_IPv4) { 1082 ip->ip_sum = in_cksum(m, hlen); 1083 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 1084 } else { 1085 KASSERT(m->m_pkthdr.csum_flags & M_CSUM_IPv4); 1086 KASSERT(M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data) >= 1087 sizeof(struct ip)); 1088 } 1089 sendorfree: 1090 /* 1091 * If there is no room for all the fragments, don't queue 1092 * any of them. 1093 */ 1094 if (ifp != NULL) { 1095 s = splnet(); 1096 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments && 1097 error == 0) { 1098 error = ENOBUFS; 1099 ipstat.ips_odropped++; 1100 IFQ_INC_DROPS(&ifp->if_snd); 1101 } 1102 splx(s); 1103 } 1104 if (error) { 1105 for (m = m0; m; m = m0) { 1106 m0 = m->m_nextpkt; 1107 m->m_nextpkt = NULL; 1108 m_freem(m); 1109 } 1110 } 1111 return (error); 1112 } 1113 1114 /* 1115 * Process a delayed payload checksum calculation. 1116 */ 1117 void 1118 in_delayed_cksum(struct mbuf *m) 1119 { 1120 struct ip *ip; 1121 u_int16_t csum, offset; 1122 1123 ip = mtod(m, struct ip *); 1124 offset = ip->ip_hl << 2; 1125 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 1126 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 1127 csum = 0xffff; 1128 1129 offset += M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data); 1130 1131 if ((offset + sizeof(u_int16_t)) > m->m_len) { 1132 /* This happen when ip options were inserted 1133 printf("in_delayed_cksum: pullup len %d off %d proto %d\n", 1134 m->m_len, offset, ip->ip_p); 1135 */ 1136 m_copyback(m, offset, sizeof(csum), (caddr_t) &csum); 1137 } else 1138 *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; 1139 } 1140 1141 /* 1142 * Determine the maximum length of the options to be inserted; 1143 * we would far rather allocate too much space rather than too little. 1144 */ 1145 1146 u_int 1147 ip_optlen(struct inpcb *inp) 1148 { 1149 struct mbuf *m = inp->inp_options; 1150 1151 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) 1152 return (m->m_len - offsetof(struct ipoption, ipopt_dst)); 1153 else 1154 return 0; 1155 } 1156 1157 1158 /* 1159 * Insert IP options into preformed packet. 1160 * Adjust IP destination as required for IP source routing, 1161 * as indicated by a non-zero in_addr at the start of the options. 1162 */ 1163 static struct mbuf * 1164 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 1165 { 1166 struct ipoption *p = mtod(opt, struct ipoption *); 1167 struct mbuf *n; 1168 struct ip *ip = mtod(m, struct ip *); 1169 unsigned optlen; 1170 1171 optlen = opt->m_len - sizeof(p->ipopt_dst); 1172 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 1173 return (m); /* XXX should fail */ 1174 if (!in_nullhost(p->ipopt_dst)) 1175 ip->ip_dst = p->ipopt_dst; 1176 if (M_READONLY(m) || M_LEADINGSPACE(m) < optlen) { 1177 MGETHDR(n, M_DONTWAIT, MT_HEADER); 1178 if (n == 0) 1179 return (m); 1180 MCLAIM(n, m->m_owner); 1181 M_MOVE_PKTHDR(n, m); 1182 m->m_len -= sizeof(struct ip); 1183 m->m_data += sizeof(struct ip); 1184 n->m_next = m; 1185 m = n; 1186 m->m_len = optlen + sizeof(struct ip); 1187 m->m_data += max_linkhdr; 1188 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1189 } else { 1190 m->m_data -= optlen; 1191 m->m_len += optlen; 1192 memmove(mtod(m, caddr_t), ip, sizeof(struct ip)); 1193 } 1194 m->m_pkthdr.len += optlen; 1195 ip = mtod(m, struct ip *); 1196 bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen); 1197 *phlen = sizeof(struct ip) + optlen; 1198 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 1199 return (m); 1200 } 1201 1202 /* 1203 * Copy options from ip to jp, 1204 * omitting those not copied during fragmentation. 1205 */ 1206 int 1207 ip_optcopy(struct ip *ip, struct ip *jp) 1208 { 1209 u_char *cp, *dp; 1210 int opt, optlen, cnt; 1211 1212 cp = (u_char *)(ip + 1); 1213 dp = (u_char *)(jp + 1); 1214 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 1215 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1216 opt = cp[0]; 1217 if (opt == IPOPT_EOL) 1218 break; 1219 if (opt == IPOPT_NOP) { 1220 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1221 *dp++ = IPOPT_NOP; 1222 optlen = 1; 1223 continue; 1224 } 1225 #ifdef DIAGNOSTIC 1226 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1227 panic("malformed IPv4 option passed to ip_optcopy"); 1228 #endif 1229 optlen = cp[IPOPT_OLEN]; 1230 #ifdef DIAGNOSTIC 1231 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1232 panic("malformed IPv4 option passed to ip_optcopy"); 1233 #endif 1234 /* bogus lengths should have been caught by ip_dooptions */ 1235 if (optlen > cnt) 1236 optlen = cnt; 1237 if (IPOPT_COPIED(opt)) { 1238 bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen); 1239 dp += optlen; 1240 } 1241 } 1242 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1243 *dp++ = IPOPT_EOL; 1244 return (optlen); 1245 } 1246 1247 /* 1248 * IP socket option processing. 1249 */ 1250 int 1251 ip_ctloutput(int op, struct socket *so, int level, int optname, 1252 struct mbuf **mp) 1253 { 1254 struct inpcb *inp = sotoinpcb(so); 1255 struct mbuf *m = *mp; 1256 int optval = 0; 1257 int error = 0; 1258 #if defined(IPSEC) || defined(FAST_IPSEC) 1259 struct lwp *l = curlwp; /*XXX*/ 1260 #endif 1261 1262 if (level != IPPROTO_IP) { 1263 error = EINVAL; 1264 if (op == PRCO_SETOPT && *mp) 1265 (void) m_free(*mp); 1266 } else switch (op) { 1267 1268 case PRCO_SETOPT: 1269 switch (optname) { 1270 case IP_OPTIONS: 1271 #ifdef notyet 1272 case IP_RETOPTS: 1273 return (ip_pcbopts(optname, &inp->inp_options, m)); 1274 #else 1275 return (ip_pcbopts(&inp->inp_options, m)); 1276 #endif 1277 1278 case IP_TOS: 1279 case IP_TTL: 1280 case IP_RECVOPTS: 1281 case IP_RECVRETOPTS: 1282 case IP_RECVDSTADDR: 1283 case IP_RECVIF: 1284 if (m == NULL || m->m_len != sizeof(int)) 1285 error = EINVAL; 1286 else { 1287 optval = *mtod(m, int *); 1288 switch (optname) { 1289 1290 case IP_TOS: 1291 inp->inp_ip.ip_tos = optval; 1292 break; 1293 1294 case IP_TTL: 1295 inp->inp_ip.ip_ttl = optval; 1296 break; 1297 #define OPTSET(bit) \ 1298 if (optval) \ 1299 inp->inp_flags |= bit; \ 1300 else \ 1301 inp->inp_flags &= ~bit; 1302 1303 case IP_RECVOPTS: 1304 OPTSET(INP_RECVOPTS); 1305 break; 1306 1307 case IP_RECVRETOPTS: 1308 OPTSET(INP_RECVRETOPTS); 1309 break; 1310 1311 case IP_RECVDSTADDR: 1312 OPTSET(INP_RECVDSTADDR); 1313 break; 1314 1315 case IP_RECVIF: 1316 OPTSET(INP_RECVIF); 1317 break; 1318 } 1319 } 1320 break; 1321 #undef OPTSET 1322 1323 case IP_MULTICAST_IF: 1324 case IP_MULTICAST_TTL: 1325 case IP_MULTICAST_LOOP: 1326 case IP_ADD_MEMBERSHIP: 1327 case IP_DROP_MEMBERSHIP: 1328 error = ip_setmoptions(optname, &inp->inp_moptions, m); 1329 break; 1330 1331 case IP_PORTRANGE: 1332 if (m == 0 || m->m_len != sizeof(int)) 1333 error = EINVAL; 1334 else { 1335 optval = *mtod(m, int *); 1336 1337 switch (optval) { 1338 1339 case IP_PORTRANGE_DEFAULT: 1340 case IP_PORTRANGE_HIGH: 1341 inp->inp_flags &= ~(INP_LOWPORT); 1342 break; 1343 1344 case IP_PORTRANGE_LOW: 1345 inp->inp_flags |= INP_LOWPORT; 1346 break; 1347 1348 default: 1349 error = EINVAL; 1350 break; 1351 } 1352 } 1353 break; 1354 1355 #if defined(IPSEC) || defined(FAST_IPSEC) 1356 case IP_IPSEC_POLICY: 1357 { 1358 caddr_t req = NULL; 1359 size_t len = 0; 1360 int priv = 0; 1361 1362 #ifdef __NetBSD__ 1363 if (l == 0 || kauth_authorize_generic(l->l_cred, 1364 KAUTH_GENERIC_ISSUSER, &l->l_acflag)) 1365 priv = 0; 1366 else 1367 priv = 1; 1368 #else 1369 priv = (in6p->in6p_socket->so_state & SS_PRIV); 1370 #endif 1371 if (m) { 1372 req = mtod(m, caddr_t); 1373 len = m->m_len; 1374 } 1375 error = ipsec4_set_policy(inp, optname, req, len, priv); 1376 break; 1377 } 1378 #endif /*IPSEC*/ 1379 1380 default: 1381 error = ENOPROTOOPT; 1382 break; 1383 } 1384 if (m) 1385 (void)m_free(m); 1386 break; 1387 1388 case PRCO_GETOPT: 1389 switch (optname) { 1390 case IP_OPTIONS: 1391 case IP_RETOPTS: 1392 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1393 MCLAIM(m, so->so_mowner); 1394 if (inp->inp_options) { 1395 m->m_len = inp->inp_options->m_len; 1396 bcopy(mtod(inp->inp_options, caddr_t), 1397 mtod(m, caddr_t), (unsigned)m->m_len); 1398 } else 1399 m->m_len = 0; 1400 break; 1401 1402 case IP_TOS: 1403 case IP_TTL: 1404 case IP_RECVOPTS: 1405 case IP_RECVRETOPTS: 1406 case IP_RECVDSTADDR: 1407 case IP_RECVIF: 1408 case IP_ERRORMTU: 1409 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1410 MCLAIM(m, so->so_mowner); 1411 m->m_len = sizeof(int); 1412 switch (optname) { 1413 1414 case IP_TOS: 1415 optval = inp->inp_ip.ip_tos; 1416 break; 1417 1418 case IP_TTL: 1419 optval = inp->inp_ip.ip_ttl; 1420 break; 1421 1422 case IP_ERRORMTU: 1423 optval = inp->inp_errormtu; 1424 break; 1425 1426 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1427 1428 case IP_RECVOPTS: 1429 optval = OPTBIT(INP_RECVOPTS); 1430 break; 1431 1432 case IP_RECVRETOPTS: 1433 optval = OPTBIT(INP_RECVRETOPTS); 1434 break; 1435 1436 case IP_RECVDSTADDR: 1437 optval = OPTBIT(INP_RECVDSTADDR); 1438 break; 1439 1440 case IP_RECVIF: 1441 optval = OPTBIT(INP_RECVIF); 1442 break; 1443 } 1444 *mtod(m, int *) = optval; 1445 break; 1446 1447 #if 0 /* defined(IPSEC) || defined(FAST_IPSEC) */ 1448 /* XXX: code broken */ 1449 case IP_IPSEC_POLICY: 1450 { 1451 caddr_t req = NULL; 1452 size_t len = 0; 1453 1454 if (m) { 1455 req = mtod(m, caddr_t); 1456 len = m->m_len; 1457 } 1458 error = ipsec4_get_policy(inp, req, len, mp); 1459 break; 1460 } 1461 #endif /*IPSEC*/ 1462 1463 case IP_MULTICAST_IF: 1464 case IP_MULTICAST_TTL: 1465 case IP_MULTICAST_LOOP: 1466 case IP_ADD_MEMBERSHIP: 1467 case IP_DROP_MEMBERSHIP: 1468 error = ip_getmoptions(optname, inp->inp_moptions, mp); 1469 if (*mp) 1470 MCLAIM(*mp, so->so_mowner); 1471 break; 1472 1473 case IP_PORTRANGE: 1474 *mp = m = m_get(M_WAIT, MT_SOOPTS); 1475 MCLAIM(m, so->so_mowner); 1476 m->m_len = sizeof(int); 1477 1478 if (inp->inp_flags & INP_LOWPORT) 1479 optval = IP_PORTRANGE_LOW; 1480 else 1481 optval = IP_PORTRANGE_DEFAULT; 1482 1483 *mtod(m, int *) = optval; 1484 break; 1485 1486 default: 1487 error = ENOPROTOOPT; 1488 break; 1489 } 1490 break; 1491 } 1492 return (error); 1493 } 1494 1495 /* 1496 * Set up IP options in pcb for insertion in output packets. 1497 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1498 * with destination address if source routed. 1499 */ 1500 int 1501 #ifdef notyet 1502 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m) 1503 #else 1504 ip_pcbopts(struct mbuf **pcbopt, struct mbuf *m) 1505 #endif 1506 { 1507 int cnt, optlen; 1508 u_char *cp; 1509 u_char opt; 1510 1511 /* turn off any old options */ 1512 if (*pcbopt) 1513 (void)m_free(*pcbopt); 1514 *pcbopt = 0; 1515 if (m == (struct mbuf *)0 || m->m_len == 0) { 1516 /* 1517 * Only turning off any previous options. 1518 */ 1519 if (m) 1520 (void)m_free(m); 1521 return (0); 1522 } 1523 1524 #ifndef __vax__ 1525 if (m->m_len % sizeof(int32_t)) 1526 goto bad; 1527 #endif 1528 /* 1529 * IP first-hop destination address will be stored before 1530 * actual options; move other options back 1531 * and clear it when none present. 1532 */ 1533 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1534 goto bad; 1535 cnt = m->m_len; 1536 m->m_len += sizeof(struct in_addr); 1537 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1538 memmove(cp, mtod(m, caddr_t), (unsigned)cnt); 1539 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1540 1541 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1542 opt = cp[IPOPT_OPTVAL]; 1543 if (opt == IPOPT_EOL) 1544 break; 1545 if (opt == IPOPT_NOP) 1546 optlen = 1; 1547 else { 1548 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1549 goto bad; 1550 optlen = cp[IPOPT_OLEN]; 1551 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1552 goto bad; 1553 } 1554 switch (opt) { 1555 1556 default: 1557 break; 1558 1559 case IPOPT_LSRR: 1560 case IPOPT_SSRR: 1561 /* 1562 * user process specifies route as: 1563 * ->A->B->C->D 1564 * D must be our final destination (but we can't 1565 * check that since we may not have connected yet). 1566 * A is first hop destination, which doesn't appear in 1567 * actual IP option, but is stored before the options. 1568 */ 1569 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1570 goto bad; 1571 m->m_len -= sizeof(struct in_addr); 1572 cnt -= sizeof(struct in_addr); 1573 optlen -= sizeof(struct in_addr); 1574 cp[IPOPT_OLEN] = optlen; 1575 /* 1576 * Move first hop before start of options. 1577 */ 1578 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1579 sizeof(struct in_addr)); 1580 /* 1581 * Then copy rest of options back 1582 * to close up the deleted entry. 1583 */ 1584 (void)memmove(&cp[IPOPT_OFFSET+1], 1585 &cp[IPOPT_OFFSET+1] + sizeof(struct in_addr), 1586 (unsigned)cnt - (IPOPT_MINOFF - 1)); 1587 break; 1588 } 1589 } 1590 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1591 goto bad; 1592 *pcbopt = m; 1593 return (0); 1594 1595 bad: 1596 (void)m_free(m); 1597 return (EINVAL); 1598 } 1599 1600 /* 1601 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1602 */ 1603 static struct ifnet * 1604 ip_multicast_if(struct in_addr *a, int *ifindexp) 1605 { 1606 int ifindex; 1607 struct ifnet *ifp = NULL; 1608 struct in_ifaddr *ia; 1609 1610 if (ifindexp) 1611 *ifindexp = 0; 1612 if (ntohl(a->s_addr) >> 24 == 0) { 1613 ifindex = ntohl(a->s_addr) & 0xffffff; 1614 if (ifindex < 0 || if_indexlim <= ifindex) 1615 return NULL; 1616 ifp = ifindex2ifnet[ifindex]; 1617 if (!ifp) 1618 return NULL; 1619 if (ifindexp) 1620 *ifindexp = ifindex; 1621 } else { 1622 LIST_FOREACH(ia, &IN_IFADDR_HASH(a->s_addr), ia_hash) { 1623 if (in_hosteq(ia->ia_addr.sin_addr, *a) && 1624 (ia->ia_ifp->if_flags & IFF_MULTICAST) != 0) { 1625 ifp = ia->ia_ifp; 1626 break; 1627 } 1628 } 1629 } 1630 return ifp; 1631 } 1632 1633 static int 1634 ip_getoptval(struct mbuf *m, u_int8_t *val, u_int maxval) 1635 { 1636 u_int tval; 1637 1638 if (m == NULL) 1639 return EINVAL; 1640 1641 switch (m->m_len) { 1642 case sizeof(u_char): 1643 tval = *(mtod(m, u_char *)); 1644 break; 1645 case sizeof(u_int): 1646 tval = *(mtod(m, u_int *)); 1647 break; 1648 default: 1649 return EINVAL; 1650 } 1651 1652 if (tval > maxval) 1653 return EINVAL; 1654 1655 *val = tval; 1656 return 0; 1657 } 1658 1659 /* 1660 * Set the IP multicast options in response to user setsockopt(). 1661 */ 1662 int 1663 ip_setmoptions(int optname, struct ip_moptions **imop, struct mbuf *m) 1664 { 1665 int error = 0; 1666 int i; 1667 struct in_addr addr; 1668 struct ip_mreq *mreq; 1669 struct ifnet *ifp; 1670 struct ip_moptions *imo = *imop; 1671 struct route ro; 1672 struct sockaddr_in *dst; 1673 int ifindex; 1674 1675 if (imo == NULL) { 1676 /* 1677 * No multicast option buffer attached to the pcb; 1678 * allocate one and initialize to default values. 1679 */ 1680 imo = (struct ip_moptions *)malloc(sizeof(*imo), M_IPMOPTS, 1681 M_WAITOK); 1682 1683 if (imo == NULL) 1684 return (ENOBUFS); 1685 *imop = imo; 1686 imo->imo_multicast_ifp = NULL; 1687 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1688 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1689 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1690 imo->imo_num_memberships = 0; 1691 } 1692 1693 switch (optname) { 1694 1695 case IP_MULTICAST_IF: 1696 /* 1697 * Select the interface for outgoing multicast packets. 1698 */ 1699 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1700 error = EINVAL; 1701 break; 1702 } 1703 addr = *(mtod(m, struct in_addr *)); 1704 /* 1705 * INADDR_ANY is used to remove a previous selection. 1706 * When no interface is selected, a default one is 1707 * chosen every time a multicast packet is sent. 1708 */ 1709 if (in_nullhost(addr)) { 1710 imo->imo_multicast_ifp = NULL; 1711 break; 1712 } 1713 /* 1714 * The selected interface is identified by its local 1715 * IP address. Find the interface and confirm that 1716 * it supports multicasting. 1717 */ 1718 ifp = ip_multicast_if(&addr, &ifindex); 1719 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1720 error = EADDRNOTAVAIL; 1721 break; 1722 } 1723 imo->imo_multicast_ifp = ifp; 1724 if (ifindex) 1725 imo->imo_multicast_addr = addr; 1726 else 1727 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1728 break; 1729 1730 case IP_MULTICAST_TTL: 1731 /* 1732 * Set the IP time-to-live for outgoing multicast packets. 1733 */ 1734 error = ip_getoptval(m, &imo->imo_multicast_ttl, MAXTTL); 1735 break; 1736 1737 case IP_MULTICAST_LOOP: 1738 /* 1739 * Set the loopback flag for outgoing multicast packets. 1740 * Must be zero or one. 1741 */ 1742 error = ip_getoptval(m, &imo->imo_multicast_loop, 1); 1743 break; 1744 1745 case IP_ADD_MEMBERSHIP: 1746 /* 1747 * Add a multicast group membership. 1748 * Group must be a valid IP multicast address. 1749 */ 1750 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1751 error = EINVAL; 1752 break; 1753 } 1754 mreq = mtod(m, struct ip_mreq *); 1755 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1756 error = EINVAL; 1757 break; 1758 } 1759 /* 1760 * If no interface address was provided, use the interface of 1761 * the route to the given multicast address. 1762 */ 1763 if (in_nullhost(mreq->imr_interface)) { 1764 bzero((caddr_t)&ro, sizeof(ro)); 1765 ro.ro_rt = NULL; 1766 dst = satosin(&ro.ro_dst); 1767 dst->sin_len = sizeof(*dst); 1768 dst->sin_family = AF_INET; 1769 dst->sin_addr = mreq->imr_multiaddr; 1770 rtalloc(&ro); 1771 if (ro.ro_rt == NULL) { 1772 error = EADDRNOTAVAIL; 1773 break; 1774 } 1775 ifp = ro.ro_rt->rt_ifp; 1776 rtfree(ro.ro_rt); 1777 } else { 1778 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1779 } 1780 /* 1781 * See if we found an interface, and confirm that it 1782 * supports multicast. 1783 */ 1784 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1785 error = EADDRNOTAVAIL; 1786 break; 1787 } 1788 /* 1789 * See if the membership already exists or if all the 1790 * membership slots are full. 1791 */ 1792 for (i = 0; i < imo->imo_num_memberships; ++i) { 1793 if (imo->imo_membership[i]->inm_ifp == ifp && 1794 in_hosteq(imo->imo_membership[i]->inm_addr, 1795 mreq->imr_multiaddr)) 1796 break; 1797 } 1798 if (i < imo->imo_num_memberships) { 1799 error = EADDRINUSE; 1800 break; 1801 } 1802 if (i == IP_MAX_MEMBERSHIPS) { 1803 error = ETOOMANYREFS; 1804 break; 1805 } 1806 /* 1807 * Everything looks good; add a new record to the multicast 1808 * address list for the given interface. 1809 */ 1810 if ((imo->imo_membership[i] = 1811 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1812 error = ENOBUFS; 1813 break; 1814 } 1815 ++imo->imo_num_memberships; 1816 break; 1817 1818 case IP_DROP_MEMBERSHIP: 1819 /* 1820 * Drop a multicast group membership. 1821 * Group must be a valid IP multicast address. 1822 */ 1823 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1824 error = EINVAL; 1825 break; 1826 } 1827 mreq = mtod(m, struct ip_mreq *); 1828 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1829 error = EINVAL; 1830 break; 1831 } 1832 /* 1833 * If an interface address was specified, get a pointer 1834 * to its ifnet structure. 1835 */ 1836 if (in_nullhost(mreq->imr_interface)) 1837 ifp = NULL; 1838 else { 1839 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1840 if (ifp == NULL) { 1841 error = EADDRNOTAVAIL; 1842 break; 1843 } 1844 } 1845 /* 1846 * Find the membership in the membership array. 1847 */ 1848 for (i = 0; i < imo->imo_num_memberships; ++i) { 1849 if ((ifp == NULL || 1850 imo->imo_membership[i]->inm_ifp == ifp) && 1851 in_hosteq(imo->imo_membership[i]->inm_addr, 1852 mreq->imr_multiaddr)) 1853 break; 1854 } 1855 if (i == imo->imo_num_memberships) { 1856 error = EADDRNOTAVAIL; 1857 break; 1858 } 1859 /* 1860 * Give up the multicast address record to which the 1861 * membership points. 1862 */ 1863 in_delmulti(imo->imo_membership[i]); 1864 /* 1865 * Remove the gap in the membership array. 1866 */ 1867 for (++i; i < imo->imo_num_memberships; ++i) 1868 imo->imo_membership[i-1] = imo->imo_membership[i]; 1869 --imo->imo_num_memberships; 1870 break; 1871 1872 default: 1873 error = EOPNOTSUPP; 1874 break; 1875 } 1876 1877 /* 1878 * If all options have default values, no need to keep the mbuf. 1879 */ 1880 if (imo->imo_multicast_ifp == NULL && 1881 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1882 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1883 imo->imo_num_memberships == 0) { 1884 free(*imop, M_IPMOPTS); 1885 *imop = NULL; 1886 } 1887 1888 return (error); 1889 } 1890 1891 /* 1892 * Return the IP multicast options in response to user getsockopt(). 1893 */ 1894 int 1895 ip_getmoptions(int optname, struct ip_moptions *imo, struct mbuf **mp) 1896 { 1897 u_char *ttl; 1898 u_char *loop; 1899 struct in_addr *addr; 1900 struct in_ifaddr *ia; 1901 1902 *mp = m_get(M_WAIT, MT_SOOPTS); 1903 1904 switch (optname) { 1905 1906 case IP_MULTICAST_IF: 1907 addr = mtod(*mp, struct in_addr *); 1908 (*mp)->m_len = sizeof(struct in_addr); 1909 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1910 *addr = zeroin_addr; 1911 else if (imo->imo_multicast_addr.s_addr) { 1912 /* return the value user has set */ 1913 *addr = imo->imo_multicast_addr; 1914 } else { 1915 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1916 *addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1917 } 1918 return (0); 1919 1920 case IP_MULTICAST_TTL: 1921 ttl = mtod(*mp, u_char *); 1922 (*mp)->m_len = 1; 1923 *ttl = imo ? imo->imo_multicast_ttl 1924 : IP_DEFAULT_MULTICAST_TTL; 1925 return (0); 1926 1927 case IP_MULTICAST_LOOP: 1928 loop = mtod(*mp, u_char *); 1929 (*mp)->m_len = 1; 1930 *loop = imo ? imo->imo_multicast_loop 1931 : IP_DEFAULT_MULTICAST_LOOP; 1932 return (0); 1933 1934 default: 1935 return (EOPNOTSUPP); 1936 } 1937 } 1938 1939 /* 1940 * Discard the IP multicast options. 1941 */ 1942 void 1943 ip_freemoptions(struct ip_moptions *imo) 1944 { 1945 int i; 1946 1947 if (imo != NULL) { 1948 for (i = 0; i < imo->imo_num_memberships; ++i) 1949 in_delmulti(imo->imo_membership[i]); 1950 free(imo, M_IPMOPTS); 1951 } 1952 } 1953 1954 /* 1955 * Routine called from ip_output() to loop back a copy of an IP multicast 1956 * packet to the input queue of a specified interface. Note that this 1957 * calls the output routine of the loopback "driver", but with an interface 1958 * pointer that might NOT be lo0ifp -- easier than replicating that code here. 1959 */ 1960 static void 1961 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst) 1962 { 1963 struct ip *ip; 1964 struct mbuf *copym; 1965 1966 copym = m_copy(m, 0, M_COPYALL); 1967 if (copym != NULL 1968 && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1969 copym = m_pullup(copym, sizeof(struct ip)); 1970 if (copym != NULL) { 1971 /* 1972 * We don't bother to fragment if the IP length is greater 1973 * than the interface's MTU. Can this possibly matter? 1974 */ 1975 ip = mtod(copym, struct ip *); 1976 1977 if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 1978 in_delayed_cksum(copym); 1979 copym->m_pkthdr.csum_flags &= 1980 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 1981 } 1982 1983 ip->ip_sum = 0; 1984 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1985 (void) looutput(ifp, copym, sintosa(dst), NULL); 1986 } 1987 } 1988
Indexes created Wed Oct 01 12:09:54 GMT 2025